Classification opinions
… calcium bentonite mixed with small amounts (1 % to 4 % by weight) of sodium carbonate (soda ash), which, when treated … the latter being preferred for applications requiring high swelling capacity in water (e.g., oil-well drilling muds, … of 5 to 7 hours, for warming the hands or feet during cold-weather activities. Application of GIR 1. Adoption : 1999 … …